The present invention relates to topical coal tar formulations in an anhydrous gel as a vehicle for the coal tar. Topical formulations containing coal tar as the active ingredient are extensively employed in the treatment of skin disorders, such as dermatitis. to be therapeutically effective, the active ingredient must be in a molecular dispersion to facilitate desired percutaneous absorption which is particularly important in achieving a therapeutic response for the management of psoriasis or eczema. Unfortunately, coal tar is practically insoluble in water. Certain organic solvents and solubilizers have been found to be good solvents for various fractions of coal tar. However, they have been found to be undesirable for commercial applications for reasons such as their high volatility and low boiling points, their disagreeable odor, and their untoward skin reaction. It is known to incorporate coal tar in an alcoholic gel base but such compositions have a drying effect on the skin and result in the production of denatured protein. Furthermore, various water-soluble emulsifiers and oil liquids or emolients have been suggested for use in preparing creams or lotions. However, because of the undesirably low solubility of the coal tar in such vehicles, higher levels of these materials in topical products are required thereby increasing their cost and also adversely affecting their cosmetic appearance.
Accordingly, in view of the above considerations, it is seen that a need exists for a suitable vehicle capable of solubilizing a sufficient amount of coal tar so that it may be employed in a topical formulation, while being dermatologically beneficial, stable and pharmaceutically acceptable.